Joel Schaefer. NDSU Extension Plant Pathologist NDSU Carrington Research Extension Center. USDA-ARS Sunflower Unit

Transcription

1 Andrew Friskop Sam Markell Blaine Schatz Scott Halley Joel Schaefer Tom Gulya Scott Meyer Febina Mathew Jim Jordahl Kevin Misek Paul Hendrickson NDSU Plant Pathology NDSU Extension Plant Pathologist NDSU Carrington Research Extension Center NDSU Langdon Research Extension Center CHS USDA-ARS Sunflower Unit NDSU Plant Pathology NDSU Plant Pathology NDSU Plant Pathology NDSU Langdon Research Extension Center NDSU Carrington Research Extension Center

2 Outline Sunflower Rust Fungicide Efficacy Trials 2008 and 2009 Fungicide Timing Trials 2008 and 2009 Analysis of both years Further topics of investigation

3 Introduction Sunflower Rust Puccinia helianthi Autoecious and macrocyclic Urediniospore economically important Earlier time of detection (ND) -Aecia Severity -Time of arrival -Environmental conditions 1. Free Moisture (Dew) 2. Temps F Sam Markell

4 Why Do We Need Fungicides? Sunflower hybrid performance tests at CREC 2009 Natural infection Oilseed (73 entries) -range = trace to 26.3% -mean = 5.3% Confection (17 entries) Leaf rust -range = 8 to 86% -mean = 57.1% Upper plant rust -range = 0 to 40% -mean = 22.7%

5 Introduction Fungicides Action threshold = 3% pustule coverage on upper four leaves Shtienberg 1995 Available chemicals QoI (Headline, Quadris) Triazoles (Folicur)

6 Fungicide Efficacy Treatment List Core Fungicides 9.0 fl oz 9.0 fl oz 5.7 fl oz 6.5 fl oz 4.0 fl oz Other Fungicides 8.0 fl oz 10.0 fl oz 4.0 fl oz -Grandin Only Experimentals Applications at R gpa, backpack sprayers

7 Fungicide Timing Treatment List Two Fungicides 9.0 fl oz 4.0 fl oz Five Treatments Non-treated R3.5 R4 R5.2 R5.5 R6+ All three timings

8 Materials and Methods: Fungicide and Timing Trials Evaluate fungicide efficacy Fungicide Trials Evaluate optimum application time Timing Trials CREC, Grandin-CHS, and LREC Inoculated (Race 336) spreader rows CREC and LREC irrigated CREC and Grandin-CHS Re-inoculated: treatment plots Multiple disease evaluations Rust severity diagrams AUDPC Yield Sam Markell

9 AUDPC = area under disease progress curve

10 AUDPC = area under disease progress curve

11 AUDPC = area under disease progress curve AUDPC

12 2008 Efficacy All fungicides reduced disease Efficacy Trials -Triazoles (Prosaro, Proline, Tebuzol, and Quash) Lower AUDPC values at 1-2% severity??

13 2009 CREC Efficacy a a a a ab bc c b b bc c c Disease Severity ~1.0% at time of applications

14 2009 Efficacy Fungicides had lower AUDPC values than non-treated control Triazoles (FRAC 3) tended to have lower AUDPC values than strobilurins (FRAC 11) and boscalid (FRAC 7) Disease Severity 0-1.0% at time of applications

15 2008 Timing Timing Trials Timing 2 (R5.2 R5.5) reduces disease as much as three applications Headline most effective at early stages of rust onset Tebuzol most effective in later stages of rust epidemic

16 2009 Data Timing CREC Disease severity (according to upper 4 leaves using severity diagrams) Yield Treatment % Sev. R3-4 R R6 R6-7 R7-8 AUDPC (lb/a) Non-treated Control 0 a a 3.95 a 12.0 a 38.5 a a f Headline (9oz) T1 = 0.5% 0 a b c 4.95 bc b b cd Tebuzol (4oz) T1 = 0.5% 0 a 0.71 ab 2.5 b b bc b ef Headline (9oz) T2 = 1.0% 0 a ab c 1.05 d d cd ab Tebuzol (4oz) T2 = 1.0% 0 a ab c 2.15 cd 8.55 de d bc Headline (9oz) T3 = 4% 0 a ab b 5.85 b cd bc de Tebuzol (4 oz) T3 = 4% 0 a 0.95 a b b d bc ef Tebuzol / Headline / Tebuzol T1, T2, T3 0 a a c d e d a Tebuzol / Headline T1, T2 0 a 1.0 a c d 14.5 d cd a Headline / Tebuzol T2, T3 0 a ab c d 4.6 e 63.9 d ab LSD

17 2009 Timing Most locations had all treatments with statistically lower AUDPC values than the non-treated control Most of the time, single application at R5.2-R5.5 (T2) had lower AUDPC values than the single applications of T1 and T3 Application of fungicide after R6+ may be too late Multiple applications had lowest AUDPC values

18 2008 and 2009 Timing Summary Headline and Tebuzol same with some exceptions R4 More trials (Data suggests too early) R6+ Too late R5 Severity threshold?

19 X = Multiple Applications U = Non-treated Control

20 What needs to be done next? We know triazoles and strobilurins reduce disease Timing is KEY! Simulate an early disease onset -Higher rust severity at early growth stages -Application at early reproductive and R5 stage -Multiple combination treatments (triazoles and strobilurins)

21 Thank You y Acknowledgements y Personnel at NDSU RECs and CHS y National Sunflower Association y ND Department of Agriculture y Chemical Companies